Heat exchanging apparatus

ABSTRACT

A heat exchanger assembly consisting of a housing and a combustion chamber and ducts provided in the housing for a fluid or gas medium which is to be heated is disclosed. The assembly consists of a central combustion chamber, and two or more arcuately-shaped shell sections enclosing the central combustion chamber and defining the ducts. One of the shell sections has inwardly directed flanges secured to walls of the central combustion chamber with edges of the remaining shell sections being secured to walls of the other of the shell sections, and the flanges are provided with apertures to provide communication between the ducts formed.

United States Patent lill Viessmann 1451 March 6, 1973 [54] HEAT EXCHANGING APPARATUS 2,751,200 6/ 1956. Peters ..122/ 149 X [76] Inventor: Hans Viessmann Im Hain, 3559 2,778,610 1/1957 Bruegger 165/154 X Battenberg/ Eder Germany Primary Examiner-Allan D. Herrmann [22] Filed: Oct. 12, 1971 Attorney-Kurt Kelman A heat exchanger assembly consisting of a housing 130] Fore-gn Apphcato Pnomy Dam and a combustion chamber and ducts provided in the Feb.9,1971 Germany P 21 05 989.2 housing fof a fluid 0f gas medium which is t0 be heated is disclosed. The assembly consists of a central [52] U.s. c1 ..122/149 165/154 combustion Chamber and W0 0f more aclaey [5l] Int Cl Izzb 7/12 shaped shell sections enclosing the central combustion [58] Field 165/154 chamber and defining the ducts. One of the shell sections has inwardly directed flanges secured to walls of [56] R f r n Cit d the central combustion chamber with edges of the e e e ces e remaining shell sections being secured to walls of the UNITED STATES PATENTS other of the shell sections, and the flanges are provided with apertures to provide communication 1,950,756 Sharp between the ducts f0rmed 2,291,985 8/1942 Powers ..165/154 X 2,692,763 10/1954 Holm 165/154 5 Claims, 3 Drawing Figures PIEMEUHAR ems HEAT EXCHANGING APPARATUS The present invention relates to a heat-exchanging apparatus, and particularly to a heat exchanger consisting of a housing arcuately-shaped acurately-shaped shell sections positioned around and enclosing a central combustion chamber.

The provision of arcuately-shaped walls in heat exchangers is generally known, for example according to the teachings of German patent No. 31,948, and British patent 291,061 dated 1929 and granted to H. Debor and entitled Improvements in Boilers, Tanks, Gas-Drums and other Containers for Resisting High lnternal Pressure, and British patent 329,882 dated 1930 and granted to A. Schenkl and entitled Central Heating Boiler and Hot Water Receptacle, and British patent 361,595 dated 1931 granted to David V. Tod and George T. Ward and entitled An Improved Boiler for Heating Water, and British patent 588,625 dated 1947 and granted to John A. Hagley and entitled lmprovements to Domestic and Ventilating Systems.

It has also already been proposed to provide for heat exchanger wall construction of this general type wherein the side and upper walls which enclose a water-conducting inner space from the outer side are divided into weak arched sectors and the crowns of the arches and/or the junctions of joining points of the arches have to be strengthened by anchor braces or struts. With all of these known type wall construction methods, however, extensive shaping work is required with corresponding machine and tool costs in order to mold the sheet metal using presses is required. In modern heat-exchanger housings having relatively large volume combustion chambers it is necessary when using thin gauge sheet metal to have to provide the structure with braces or struts in order to achieve the necessary rigidity and as a result relatively expensive measures then have to be taken in order to install the necessary bracing by providing holes in adjacent wall surfaces for the anchoring of the bracings, and then perforating the anchor braces, and then welding the anchor braces in a leak-proof manner from the outside and then subsequently brazing the anchor braces in order to provide a strong and durable welding junction capable of withstanding the pressure to which it will be subjected.

The present invention overcomes the disadvantages of the known prior art constructions by providing a heat exchanger assembly which is simple and economical in construction and without the necessity of having to provide additional bracing structures.

According to the present invention the heatexchanger housing is constructed having at least two arcuately shaped or U-shaped shell sections which arch outwardly and with at least one of the shell sections being provided with inwardly directed flanges which are welded or otherwise secured to a centrally positioned combustion chamber, and with the remaining arcuately shaped shell sections being welded or otherwise secured to the said one of the shell sections.

In such a construction the arcuately shaped shell sections are positioned around a central combustion chamber and are welded together where there edges meet, and the sections having the inwardly directed flanges are welded to the combustion chamber where the inner edges of the flanges meet the chamber.

According to the present invention it is possible to provide a simple method for the manufacture of a complete heat-exchanger housing which accordingly permits joining of the combustion chamber and outer duct assembliesvto be made cheaply and without the necessity of having to use special anchor braces or struts.

ln constructing an assembly according to the present invention wherein four shell sections are used two opposed shell sections are provided with inwardly directed flanges which are welded or otherwise secured to the walls of the central combustion chamber and the remaining two shell sections are then positioned above and below the two opposed shell sections and are welded thereto in a simple manner.

The present inventive concept will now be more specifically described with reference to the embodiment shown in the accompanying drawings wherein:

FIG. 1 illustrates in schematic perspective view one embodiment of the present invention and wherein two arcuately-shaped shell sections are employed,

FIG. 2 is a further embodiment of a construction of a heat-exchanger .assembly according to the present invention shown in schematic perspective view and wherein four shell sections are employed, and

FIG. 3 is a top schematic view of a portion of a flange section of one shell section having apertures or perforations formed therein.

With reference now to the drawings in detail, in FIG. 1, numeral l represents a top shell section and numeral 2 represents a lower shell section, both of which component parts have been formed in an arcuate or- U- shaped configuration by a rolling mill machine operation. The lower shell section 2 is provided with inwardly directed flanges 4 which abut against and are welded to side walls 6 of a central combustion chamber 7. The lower edges 3 of top or upper section l abut against the walls of lower shell 2 adjacent the flanges 4 and the two shells are welded together along these lines of abutment. The flanges 4 are provided with openings or apertures 5.

After this initial construction the structure is provided with front and rear walls (which are not shown in the drawings) by means of which an enclosed heatexchanger housing is provided. Also not illustrated in the accompanying drawings is the joining of the heating gas ducts 13 to the central combustion chamber 7 as the attached drawings are provided to show only the general principles of constructing a heat exchanger assembly according to the present invention.

In the embodiments shown in attached FIG. 2 an assembly similar to that shown in FIG. l is illustrated. In the embodiment shown in FIG. 2 the complete heat exchanger housing assembly consists of four shell sections numbering 8, 9, l0 and 1l positioned around a central combustion chamber 7 which is provided with upper and lower extensions 7'. The two opposed sections 9 and 10 are provided with inwardly directed flanges l2 which abut against and are welded to the chamber 7, and the upper and lower sections 8 and l1 abut against the walls of the two opposed sections 9 and l0 and are welded thereto at these lines of abutment. The flanges l2 of the opposed sections 9 and 10 are of course provided with suitable apertures 5 to provide communication between the various cavities formed by the assembly of the shell sections.

In the attached drawings, the firing means for the combustion chamber has not been illustrated as such means may be of known construction and design.

lt will be appreciated that by using the design construction shown in the attached drawings that the welded assembly is both strong and durable and economical in construction, and avoids the necessity of having to use additional structural bracesA which of course adds to the cost of making any heat exchanger assembly.

lt will be clear that instead of employing flanges l2 of sections 9 and l0 as a means of joining the sections to the combustion chamber, that inwardly directed flanges could be provided on the sections 8 and l l with these latter sections then being secured to the combustion chamber, and the sections 9 and l0 would then be secured or welded to the sections 8 and ll.

ln FIGS. l and 2 heating gas ducts are indicated by numeral 13 but the connections between these ducts and the central combustion chamber 7 are not shown in the drawings inasmuch as such connections can be made in known manner.

ln the heat-exchanger assembly illustrated in FIG. l the heating gas may be withdrawn from the combustion chamber 7 either from the rear or from the front with the result that it can then flow into the heating gas ducts from either the'rear or the front of these ducts. The combustion gas outlet connections would then be arranged accordingly.

FIG. 2 illustrates a combustion chamber 7 conforming exactly to the combustion size of a combustion llame and the heating gases flow through the combustion chamber flues 7- to the front of the assembly where they then enter the heating gas ducts 13. Clearly these exchanger assemblies shown in the attached drawings will be enclosed in outer coverings or casings which are not illustrated in the' accompanying drawings l. A heat exchanger assembly consisting of a housing and a combustion chamber and ducts provided in the housing for a fluid or gas medium which is to be heated, comprising a central combustion chamber, and at least two arcuately-shaped shell sections enclosing the said central combustion chamber and defining said ducts, one of the said shell sections having inwardly directed flanges secured to walls of the central combustion chamber, with edges of the remaining shell sections being secured to walls of the said one of the said shell sections, the said flanges having apertures to provide communication between said ducts.

2. A heat exchanger assembly according to claim l consisting of four sections enclosing the central combustion chamber, two opposed shell sections having inwardly directed flanges secured to walls of the combustion chamber, edges of the other two shell sections being secured to walls of the said two opposed shell sections to provide fluid or gas ducts completely enclosing the central combustion chamber.

3. A heat exchanger assembly according to claim l wherein the central combustion chamber is generally rectangular in cross-section, having two generally U- shaped shell sections in vcross-section provided therearound. v

4. A heat exchanger assembly according to claim l` wherein the said shell sections are secured tothe central combustion chamber and to each other by welding. 5. A heat exchanger assembly according to claim l, said ducts containing heating ducts communicating with said combustion chamber.

lll Il! 

1. A heat exchanger assembly consisting of a housing and a combustion chamber and ducts provided in the housing for a fluid or gas medium which is to be heated, comprising a central combustion chamber, and at least two arcuately-shaped shell sections enclosing the said central combustion chamber and defining said ducts, one of the said shell sections having inwardly directed flanges secured to walls of the central combustion chamber, with edges of the remaining shell sections being secured to walls of the said one of the said shell sections, the said flanges having apertures to provide communication between said ducts.
 1. A heat exchanger assembly consisting of a housing and a combustion chamber and ducts provided in the housing for a fluid or gas medium which is to be heated, comprising a central combustion chamber, and at least two arcuately-shaped shell sections enclosing the said central combustion chamber and defining said ducts, one of the said shell sections having inwardly directed flanges secured to walls of the central combustion chamber, with edges of the remaining shell sections being secured to walls of the said one of the said shell sections, the said flanges having apertures to provide communication between said ducts.
 2. A heat exchanger assembly according to claim 1 consisting of four sections enclosing the central combustion chamber, two opposed shell sections having inwardly directed flanges secured to walls of the combustion chamber, edges of the other two shell sections being secured to walls of the said two opposed shell sections to provide fluid or gas ducts completely enclosing the central combustion chamber.
 3. A heat exchanger assembly according to claim 1 wherein the central combustion chamber is generally rectangular in cross-section, having two generally U-shaped shell sections in cross-section provided therearound.
 4. A heat exchanger assembly according to claim 1 wherein the said shell sections are secured to the central combustion chamber and to each other by welding. 